1. Field of the Invention
The present invention relates generally to the treatment of intracranial hemorrhages, and more specifically, to the treatment of intracranial hemorrhages using an ultrasound catheter.
2. Background of the Invention
Up to 70,000 Americans each year suffer a hemorrhagic stroke. Most of these occur in the basal ganglia, and a third of those include bleeding into the ventricles. Half of these victims will die within months, and a quarter of the survivors will have a second stroke within five years.
Bleeding in the brain occurs due to high blood pressure, aneurysms, and less frequently arterio-venous malformations (AVM), and increases in incidence with age. Factors including smoking, diabetes, and obesity play roles, as do amyloid deposits in the elderly.
With respect to stroke treatment, up to 7,000 cases per year involve surgical intervention. The objectives of surgical intervention generally include clipping bleeding aneurysms, removing bleeding AVMs, and removing clot volume in intracranial hemorrhages (ICH).
In certain applications, an interventional radiologist will insert Goldvalve detachable balloons, Guglielmi detachable coils, or Onyx liquid embolic to occlude AVMs and saccular aneurysm. These applications are primarily preventive (e.g., preventing a second bleed). Other methods of reducing further bleeding include using embolics and FVIIa, and/or maintaining intracranial pressure below mean arterial pressure. Medical therapy typically also includes head elevation, Tylenol for temperature reduction, paralytics to prevent coughing, intubation to prevent aspiration, Mannitol and diuretics to reduce fluid volume, and seizure preventatives.
Recently, lytics have been considered as a treatment option to remove obstruction in the ventricles and to reduce intracranial pressure. However, such lytic treatment has not been widely adopted because it is generally considered too slow to provide sufficient clinical benefits.
Accordingly, it would be desirable to provide a method and apparatus for rapidly reducing the volume of the blood clot in the patient's brain.